Water electrolysis hydrogen production system

Abstract

The invention provides a water electrolysis hydrogen production system, which comprises a first converter, a second converter, a third converter, a fourth converter and a fourth converter, wherein the first input end and the first output end of the first converter are connected with an alternating-current power supply; the N first capacitors are connected in series, the first ends of the N first capacitors connected in series are connected with the second output end of the first converter, and the second ends of the N first capacitors connected in series are connected with the second input end of the first converter; the input end or the output end of each first electrolytic cell is provided with a first switch, each first electrolytic cell is connected with a different first capacitor in parallel through the first switch, and each first electrolytic cell is used for electrolyzing water to prepare hydrogen under the condition of electrification; wherein under the condition that the first target electrolytic cell needs to be shut down, a first switch connected with the first target electrolytic cell is turned on; and turning off the first switch connected with the first target electrolytic cell under the condition that the first target electrolytic cell recovers to work. The water electrolysis hydrogen production efficiency can be improved.

Description

Technical Field

[0001] The present application relates to the field of energy technology, and in particular to a water electrolysis hydrogen production system. Background Art

[0002] Hydrogen energy has the characteristics of no pollution, high calorific value, convenient storage and transportation, and has great development potential. In the related technology, hydrogen is usually prepared by electrolyzing water in an electrolyzer. However, in the related technology, in the process of preparing hydrogen by electrolyzing water in multiple electrolyzers, the multiple electrolyzers are electrically connected end to end. If one of the electrolyzers has an abnormality and needs to be shut down for maintenance, all the electrolyzers need to be shut down, resulting in low efficiency of preparing hydrogen by electrolyzing water.

[0003] It can be seen that the related technology has the problem of low efficiency in preparing hydrogen by electrolyzing water. Summary of the invention

[0004] The embodiment of the present application provides a system for producing hydrogen by electrolysis of water to solve the problem of low efficiency in producing hydrogen by electrolysis of water in the related art.

[0005] In order to solve the above problems, the present application provides a water electrolysis hydrogen production system, comprising:

[0006] a first converter, wherein the first input terminal and the first output terminal of the first converter are used to connect to an AC power source, and the first converter is used to convert an AC current into a DC current;

[0007] N first capacitors, the N first capacitors are connected in series, a first end of the N first capacitors connected in series is connected to the second output end of the first converter, a second end of the N first capacitors connected in series is connected to the second input end of the first converter, and N is a positive integer greater than or equal to 2;

[0008] N first electrolytic cells, wherein the input end or the output end of each of the N first electrolytic cells is provided with a first switch, each of the first electrolytic cells is respectively connected in parallel with a different first capacitor through the first switch, and each of the first electrolytic cells is used to electrolyze water to produce hydrogen when powered;

[0009] Among them, when the first target electrolytic cell needs to be shut down, the first switch connected to the first target electrolytic cell is opened; when the first target electrolytic cell is restored to work, the first switch connected to the first target electrolytic cell is closed, and the first target electrolytic cell is one of the N first electrolytic cells.

[0010] In one embodiment, the water electrolysis hydrogen production system further comprises:

[0011] N first voltage equalizing units are connected in series, and each of the first voltage equalizing units is respectively connected in parallel with a different first capacitor, the first ends of the N first voltage equalizing units connected in series are connected to the second output end of the first converter, and the second ends of the N first voltage equalizing units connected in series are connected to the second input end of the first converter, and each first voltage equalizing unit is used to adjust the voltage of each first capacitor so that the voltage of each first capacitor is the same.

[0012] In one embodiment, the water electrolysis hydrogen production system further comprises:

[0013] N second converters, wherein a first input end of each second converter of the N second converters is connected to a first end of a first capacitor, a first output end of each second converter is connected to a second end of the same first capacitor, and each second converter is used to convert an input direct current into a direct current of a different magnitude;

[0014] N second capacitors, each of the N second capacitors is connected in parallel with a different first electrolytic cell, a first end of each second capacitor is connected to a second input end of a second converter, and a first end of each second capacitor is connected to a second output end of the same second converter.

[0015] In one embodiment, each of the N first voltage balancing units is a resistor, wherein:

[0016] The input end of the resistor is connected to the input end of the first capacitor, and the input end of the resistor is also connected to the output end of an adjacent resistor or the second output end of the first converter;

[0017] The output end of the resistor is connected to the output end of the first capacitor, and the output end of the resistor is also connected to the input end of an adjacent resistor or the second input end of the first converter.

[0018] In one embodiment, each of the N first voltage balancing units is a voltage stabilizing diode, wherein:

[0019] The input end of the voltage zener diode is connected to the input end of the first capacitor, and the input end of the voltage zener diode is also connected to the output end of an adjacent voltage zener diode or the second output end of the first converter;

[0020] The output end of the voltage zener diode is connected to the output end of the first capacitor, and the output end of the voltage zener diode is also connected to the input end of an adjacent voltage zener diode or the second input end of the first converter.

[0021] In one embodiment, each of the N first voltage balancing units is composed of at least two rectifier diodes, and the at least two rectifier diodes are connected in series, wherein:

[0022] The input end of the series-connected rectifier diodes is connected to the input end of the first capacitor, and the input end of the series-connected rectifier diodes is also connected to the output end of the adjacent series-connected rectifier diodes or the second output end of the first converter;

[0023] The output end of the series-connected rectifier diodes is connected to the output end of the first capacitor, and the output end of the series-connected rectifier diodes is also connected to the input end of an adjacent series-connected rectifier diode or the second input end of the first converter.

[0024] In one embodiment, the water electrolysis hydrogen production system further comprises:

[0025] N third capacitors, the N third capacitors are connected in series, a first end of the N third capacitors connected in series is connected to the second output end of the first converter, and a second end of the N third capacitors connected in series is connected to the second input end of the first converter;

[0026] N second electrolytic cells, wherein the input end or the output end of each of the N second electrolytic cells is provided with a second switch, each of the second electrolytic cells is respectively connected in parallel with a different third capacitor through the second switch, and each of the second electrolytic cells is used to electrolyze water to produce hydrogen when powered;

[0027] Among them, when the second target electrolytic cell needs to be shut down, the second switch connected to the second target electrolytic cell is opened; when the second target electrolytic cell is restored to work, the second switch connected to the second target electrolytic cell is closed, and the second target electrolytic cell is one of the N second electrolytic cells.

[0028] In one embodiment, the water electrolysis hydrogen production system further comprises:

[0029] N second voltage balancing units, the N second voltage balancing units are connected in series, and each of the second voltage balancing units is respectively connected in parallel with a different third capacitor, the first ends of the N second voltage balancing units connected in series are connected to the second output end of the first converter, the second ends of the N second voltage balancing units connected in series are connected to the second input end of the first converter, and each first voltage balancing unit is used to adjust the voltage of each third capacitor so that the voltage of each third capacitor is the same.

[0030] In one embodiment, the water electrolysis hydrogen production system further comprises:

[0031] N third converters, wherein a first input terminal of each of the N third converters is connected to a first terminal of a third capacitor, a first output terminal of each of the third converters is connected to a second terminal of the same third capacitor, and each of the third converters is used to convert an input direct current into a direct current of a different magnitude;

[0032] N fourth capacitors, each of the N fourth capacitors is respectively connected in parallel with a different second electrolytic cell, a first end of each fourth capacitor is connected to a second input end of a third converter, and a first end of each fourth capacitor is connected to a second output end of the same third converter.

[0033] In one embodiment, the N first electrolytic cells include a working electrolytic cell and a spare electrolytic cell, and / or the N second electrolytic cells include a working electrolytic cell and a spare electrolytic cell.

[0034] One of the above technical solutions has the following advantages or beneficial effects:

[0035] In an embodiment of the present application, the water electrolysis hydrogen production system includes: a first converter, the first input end and the first output end of the first converter are used to connect to an AC power supply, and the first converter is used to convert AC current into DC current; N first capacitors, the N first capacitors are connected in series, the first ends of the N first capacitors after series connection are connected to the second output end of the first converter, and the second ends of the N first capacitors after series connection are connected to the second input end of the first converter, and N is a positive integer greater than or equal to 2; N first electrolytic cells, the input end or output end of each of the N first electrolytic cells is provided with a first switch, each first electrolytic cell is connected in parallel with a different first capacitor through the first switch, and each first electrolytic cell is used to electrolyze water to produce hydrogen when powered on. In this way, when the first target electrolyzer needs to be shut down, the first switch connected to the first target electrolyzer is opened; when the first target electrolyzer is restored to work, the first switch connected to the first target electrolyzer is closed. The first target electrolyzer is one of the N first electrolyzers. Since the first electrolyzers are connected in parallel to each other, stopping the first target electrolyzer will not affect the normal operation of other first electrolyzers, thereby improving the efficiency of preparing hydrogen by electrolyzing water. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0037] Figure 1It is a structural schematic diagram of a water electrolysis hydrogen production system provided in an embodiment of the present application;

[0038] Figure 2 is a circuit diagram of an electrolytic cell in the related art provided in an embodiment of the present application;

[0039] Figure 3 is an equivalent circuit diagram of an electrolytic cell in the related art provided in an embodiment of the present application;

[0040] Figure 4 is a circuit diagram of a first electrolytic cell provided in an embodiment of the present application;

[0041] Figure 5 is an equivalent circuit diagram of the first electrolytic cell provided in an embodiment of the present application;

[0042] Figure 6 It is one of the circuit schematic diagrams of the first voltage balancing unit provided in the embodiment of the present application;

[0043] Figure 7 This is the second circuit diagram of the first voltage balancing unit provided in the embodiment of the present application;

[0044] Figure 8 This is the third circuit diagram of the first voltage balancing unit provided in the embodiment of the present application;

[0045] Fig. 9 is a structural schematic diagram of a water electrolysis hydrogen production system including a second electrolyzer provided in an embodiment of the present application;

[0046] Fig.10 It is a schematic diagram of the spare electrolytic cell and the working electrolytic cell provided in the embodiment of the present application. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] See also Figure 1 , Figure 1 Schematic diagram of a water electrolysis hydrogen production system provided in an embodiment of the present application. Figure 1 As shown, the water electrolysis hydrogen production system includes:

[0049] A first converter U1, wherein a first input terminal and a first output terminal of the first converter U1 are used to connect to an AC power source, and the first converter U1 is used to convert an AC current into a DC current;

[0050] N first capacitors C1, the N first capacitors C1 are connected in series, the first ends of the N first capacitors C1 connected in series are connected to the second output end of the first converter U1, and the second ends of the N first capacitors C1 connected in series are connected to the second input end of the first converter U1, and N is a positive integer greater than or equal to 2;

[0051] N first electrolytic cells R1, wherein the input end or the output end of each of the N first electrolytic cells R1 is provided with a first switch, each of the first electrolytic cells R1 is respectively connected in parallel with a different first capacitor C1 through the first switch, and each of the first electrolytic cells R1 is used to electrolyze water to produce hydrogen when powered on;

[0052] Among them, when the first target electrolytic cell needs to be shut down, the first switch connected to the first target electrolytic cell is opened; when the first target electrolytic cell is restored to work, the first switch connected to the first target electrolytic cell is closed, and the first target electrolytic cell is one of the N first electrolytic cells R1.

[0053] The first converter U1 is an AC / DC converter. The first input terminal and the first output terminal of the first converter U1 are used to directly connect the positive and negative electrodes of the AC power source, convert the AC current into a DC current, and then supply the DC current to the first electrolyzer R1 for electrolyzing water to produce hydrogen. The AC power source can be a city power supply, or a wind turbine or a photovoltaic generator, and the storage of excess electrical energy is achieved by converting electrical energy into hydrogen energy.

[0054] The first capacitor C1 is connected in series to convert the voltage V output by the first converter U1 bus Specifically, the first ends of the N first capacitors C1 connected in series are connected to the second output end of the first converter U1, and the second ends of the N first capacitors C1 connected in series are connected to the second input end of the first converter U1, so that the first converter U1 supplies power to each of the N first capacitors C1, and each first capacitor C1 is connected in parallel to a first electrolytic tank R1, thereby supplying power to each first electrolytic tank R1.

[0055] The first electrolytic cell R1 is used to electrolyze water to produce hydrogen, wherein the first electrolytic cell R1 is connected in parallel with a first capacitor C1, and the voltage V output by the first converter U1 is converted by the first capacitor C1. bus The divided voltage is used to electrolyze water to produce hydrogen. The positive electrode and the negative electrode of each first electrolytic cell R1 are connected to a pipeline, and the generated hydrogen and oxygen are collected through the pipeline.

[0056] It should be understood that in the related art, some circuits of the electrolytic cell such as Figure 2 The corresponding equivalent circuit is shown as Figure 3 As shown, from Figure 2 and Figure 3 It can be seen that each first electrolytic cell R1 is connected in series. If one first electrolytic cell R1 is abnormal and needs to be stopped, all electrolytic cells need to be powered off and stop working. In the embodiment of the present application, part of the circuit of the first electrolytic cell R1 is as follows: Figure 4 The corresponding equivalent circuit is shown as Figure 5 As shown, from Figure 4 and Figure 5 It can be seen that each first electrolytic cell R1 is connected in parallel. When an abnormality occurs in a first electrolytic cell R1 and needs to be stopped, the first switch located at the input end or the output end of the first electrolytic cell R1 is disconnected, while the other first electrolytic cells R1 are still connected to the first capacitor C1. In this case, the other first electrolytic cells R1 can still work.

[0057] In an embodiment of the present application, the water electrolysis hydrogen production system includes: a first converter U1, the first input end and the first output end of the first converter U1 are used to connect to an AC power supply, and the first converter U1 is used to convert AC current into DC current; N first capacitors C1, the N first capacitors C1 are connected in series, the first ends of the N first capacitors C1 after series connection are connected to the second output end of the first converter U1, and the second ends of the N first capacitors C1 after series connection are connected to the second input end of the first converter U1, and N is a positive integer greater than or equal to 2; N first electrolytic cells R1, the input end or output end of each first electrolytic cell R1 in the N first electrolytic cells R1 is provided with a first switch, each first electrolytic cell R1 is connected in parallel with a different first capacitor C1 through the first switch, and each first electrolytic cell R1 is used to electrolyze water to produce hydrogen when power is turned on. In this way, when the first target electrolyzer needs to be shut down, the first switch connected to the first target electrolyzer is opened; when the first target electrolyzer is restored to work, the first switch connected to the first target electrolyzer is closed. The first target electrolyzer is one of the N first electrolyzers R1. Since the first electrolyzers R1 are connected in parallel to each other, stopping the first target electrolyzer will not affect the normal operation of other first electrolyzers R1, thereby improving the efficiency of preparing hydrogen by electrolyzing water.

[0058] In one embodiment, the water electrolysis hydrogen production system further comprises:

[0059] N first voltage equalizing units U2 are connected in series, and each of the first voltage equalizing units U2 is respectively connected in parallel with a different first capacitor C1, the first ends of the N first voltage equalizing units U2 connected in series are connected to the second output end of the first converter U1, the second ends of the N first voltage equalizing units U2 connected in series are connected to the second input end of the first converter U1, and each first voltage equalizing unit U2 is used to adjust the voltage of each first capacitor C1 so that the voltage of each first capacitor C1 is the same.

[0060] It should be understood that during the process of hydrogen production by electrolysis of different first electrolyzers R1, the internal resistance of the electrolyzer changes due to factors such as the electrolyte flow rate and parameter aging of the electrolyzer, resulting in fluctuations in hydrogen production efficiency and a decrease in the efficiency of hydrogen production by electrolysis of the entire system. To avoid this situation, it is necessary to control the operating voltage of each first electrolyzer R1 to be the same, so that each first electrolyzer R1 can produce hydrogen by electrolysis of water according to the set power.

[0061] The first voltage balancing unit U2 is used to adjust the voltage of each first capacitor C1 so that the voltage of each first capacitor C1 is the same, thereby enabling each first electrolyzer R1 to electrolyze water to produce hydrogen with the same input voltage, thereby avoiding the situation where different first electrolyzers R1 have different power of electrolyzing water to produce hydrogen.

[0062] The first voltage balancing unit U2 may be a resistor, at least two diodes or a voltage stabilizing diode D1.

[0063] In an embodiment of the present application, the water electrolysis hydrogen production system includes N first voltage equalizing units U2, the N first voltage equalizing units U2 are connected in series, and each first voltage equalizing unit U2 is respectively connected in parallel with a different first capacitor C1, the first ends of the N first voltage equalizing units U2 connected in series are connected to the second output end of the first converter U1, and the second ends of the N first voltage equalizing units U2 connected in series are connected to the second input end of the first converter U1, and each first voltage equalizing unit U2 is used to adjust the voltage of each first capacitor C1 so that the voltage of each first capacitor C1 is the same, thereby avoiding the problem of fluctuations in hydrogen production efficiency due to changes in the internal resistance of the electrolytic cell, and a decrease in the efficiency of the entire system for hydrogen production by water electrolysis.

[0064] In one embodiment, the water electrolysis hydrogen production system further comprises:

[0065] N second converters U3, wherein a first input end of each second converter U3 of the N second converters U3 is connected to a first end of a first capacitor C1, a first output end of each second converter U3 is connected to a second end of the same first capacitor C1, and each second converter U3 is used to convert an input direct current into a direct current of different magnitudes;

[0066] N second capacitors C2, each of the N second capacitors C2 is respectively connected in parallel with a different first electrolytic tank R1, a first end of each second capacitor C2 is connected to a second input end of a second converter U3, and a first end of each second capacitor C2 is connected to a second output end of the same second converter U3.

[0067] The second converter U3 is a direct current / direct current (DC / DC) converter, and the second converter U3 is used to convert the input direct current into direct currents of different magnitudes, and the first electrolyzer R1 is controlled to electrolyze water to produce hydrogen at different set powers through the second converter U3. The second capacitor C2 is used to filter the voltage input to the first electrolyzer R1 to stabilize the voltage input to the first electrolyzer R1.

[0068] It should be understood that for different first electrolyzers R1, their working environments are different, and different working powers need to be set for them so that each first electrolyzer R1 can produce hydrogen with a higher efficiency of hydrogen production by electrolysis of water. In the embodiment of the present application, by setting the second converter U3 and the second capacitor C2, the first electrolyzer R1 is connected in parallel with the second capacitor C2 and the second converter U3, so that the hydrogen production power of the first electrolyzer R1 can be controlled by adjusting the conversion parameters of the second converter U3.

[0069] In the embodiment of the present application, the water electrolysis hydrogen production system also includes: N second converters U3, the first input end of each second converter U3 in the N second converters U3 is connected to the first end of a first capacitor C1, the first output end of each second converter U3 is connected to the second end of the same first capacitor C1, and each second converter U3 is used to convert the input DC current into a DC current of different sizes; N second capacitors C2, each second capacitor C2 in the N second capacitors C2 is respectively connected in parallel with a different first electrolyzer R1, the first end of each second capacitor C2 is connected to the second input end of a second converter U3, and the first end of each second capacitor C2 is connected to the second output end of the same second converter U3. In this way, by setting the second converter U3 and the second capacitor C2, the first electrolyzer R1 is connected in parallel with the second capacitor C2 and the second converter U3, so that the hydrogen production power of the first electrolyzer R1 can be controlled by adjusting the conversion parameters of the second converter U3.

[0070] In one embodiment, Figure 6 As shown, each of the N first voltage balancing units U2 is a resistor R0, wherein:

[0071] The input end of the resistor R0 is connected to the input end of the first capacitor C1, and the input end of the resistor R0 is also connected to the output end of the adjacent resistor R0 or the second output end of the first converter U1;

[0072] The output end of the resistor R0 is connected to the output end of the first capacitor C1 , and the output end of the resistor R0 is also connected to the input end of the adjacent resistor R0 or the second input end of the first converter U1 .

[0073] It should be understood that each first voltage equalizing unit U2 is a resistor R0, and the resistance value of each resistor R0 is the same, and the first capacitor C1 is also the same. In this way, the resistor R0 is connected in parallel with the first capacitor C1, so that the distributed voltage of each first capacitor C1 is the same, so that the voltage input to the second converter U3 or the voltage input to the first electrolytic tank R1 is the same.

[0074] The voltage of the first capacitor C1 after voltage division is 1.7V-1.9V.

[0075] In the embodiment of the present application, each of the N first voltage balancing units U2 is a resistor R0, wherein the input end of the resistor R0 is connected to the input end of the first capacitor C1, and the input end of the resistor R0 is also connected to the output end of the adjacent resistor R0 or the second output end of the first converter U1; the output end of the resistor R0 is connected to the output end of the first capacitor C1, and the output end of the resistor R0 is also connected to the input end of the adjacent resistor R0 or the second input end of the first converter U1. In this way, by connecting the resistor R0 in parallel with the first capacitor C1, the voltage allocated to each first capacitor C1 is the same, so that the voltage input to the second converter U3 or the voltage input to the first electrolytic cell R1 is the same.

[0076] In one embodiment, Figure 7 As shown, each of the N first voltage balancing units U2 is a voltage stabilizing diode D1, wherein:

[0077] The input end of the voltage zener diode D1 is connected to the input end of the first capacitor C1, and the input end of the voltage zener diode D1 is also connected to the output end of the adjacent voltage zener diode D1 or the second output end of the first converter U1;

[0078] The output end of the Zener diode D1 is connected to the output end of the first capacitor C1 , and the output end of the Zener diode D1 is also connected to the input end of an adjacent Zener diode D1 or the second input end of the first converter U1 .

[0079] The positive electrode of the above-mentioned voltage zener diode D1 is the input terminal, connected to the end of the first capacitor C1 close to the output terminal of the first converter U1; the negative electrode of the above-mentioned voltage zener diode D1 is the output terminal, connected to the end of the first capacitor C1 close to the input terminal of the first converter U1. In the case where the voltage of the first capacitor C1 exceeds the breakdown voltage of the voltage zener diode D1, the voltage zener electrode tube is broken down. By connecting the voltage zener electrode tube in parallel with the first capacitor C1, the voltage of the first capacitor C1 does not exceed the breakdown voltage of the voltage zener electrode tube, thereby controlling the voltage of each first capacitor C1 to be the same.

[0080] The breakdown voltage of each voltage-stabilizing electrode tube is the same, so that the voltage of each first capacitor C1 is the same.

[0081] In the embodiment of the present application, each of the N first voltage-equalizing units U2 is a voltage-stabilizing diode D1, wherein the input end of the voltage-stabilizing diode D1 is connected to the input end of the first capacitor C1, and the input end of the voltage-stabilizing diode D1 is also connected to the output end of the adjacent voltage-stabilizing diode D1 or the second output end of the first converter U1; the output end of the voltage-stabilizing diode D1 is connected to the output end of the first capacitor C1, and the output end of the voltage-stabilizing diode D1 is also connected to the input end of the adjacent voltage-stabilizing diode D1 or the second input end of the first converter U1. In this way, when the voltage of the first capacitor C1 exceeds the breakdown voltage of the voltage-stabilizing diode D1, the voltage-stabilizing electrode tube is broken down, and by connecting the voltage-stabilizing electrode tube in parallel with the first capacitor C1, the voltage of the first capacitor C1 does not exceed the breakdown voltage of the voltage-stabilizing electrode tube, thereby controlling the voltage of each first capacitor C1 to be the same.

[0082] In one embodiment, Figure 8 As shown, each of the N first voltage balancing units U2 is composed of at least two rectifier diodes D2, and the at least two rectifier diodes D2 are connected in series, wherein:

[0083] The input end of the series-connected rectifier diode D2 is connected to the input end of the first capacitor C1, and the input end of the series-connected rectifier diode D2 is also connected to the output end of the adjacent series-connected rectifier diode D2 or the second output end of the first converter U1;

[0084] The output end of the series-connected rectifier diodes D2 is connected to the output end of the first capacitor C1 , and the output end of the series-connected rectifier diodes D2 is also connected to the input end of an adjacent series-connected rectifier diode D2 or the second input end of the first converter U1 .

[0085] The above-mentioned rectifier diode D2 is similar to a voltage-stabilizing electrode tube. When the voltage between the input and output ends of the rectifier diode D2 exceeds the set voltage, the rectifier diode D2 is turned on. By connecting the series-connected rectifier diode D2 in parallel with the first capacitor C1, the voltage of the first capacitor C1 does not exceed the turn-on voltage of the series-connected rectifier diode D2, thereby controlling the voltage of each first capacitor C1 to be the same.

[0086] The conduction voltage of the rectifier diode D2 connected in parallel with each first capacitor C1 is the same.

[0087] In the embodiment of the present application, each of the N first voltage balancing units U2 is at least two rectifier diodes D2, and at least two rectifier diodes D2 are connected in series, wherein the input end of the rectifier diodes D2 connected in series is connected to the input end of the first capacitor C1, and the input end of the rectifier diodes D2 connected in series is also connected to the output end of the adjacent rectifier diodes D2 connected in series or the second output end of the first converter U1; the output end of the rectifier diodes D2 connected in series is connected to the output end of the first capacitor C1, and the output end of the rectifier diodes D2 connected in series is also connected to the input end of the adjacent rectifier diodes D2 connected in series or the second input end of the first converter U1. In this way, by connecting the rectifier diodes D2 connected in series in parallel with the first capacitor C1, the voltage of the first capacitor C1 does not exceed the conduction voltage of the rectifier diodes D2 connected in series, thereby controlling the voltage of each first capacitor C1 to be the same.

[0088] In one embodiment, Fig. 9 As shown, the water electrolysis hydrogen production system also includes:

[0089] N third capacitors C3, the N third capacitors C3 are connected in series, the first ends of the N third capacitors C3 connected in series are connected to the second output end of the first converter U1, and the second ends of the N third capacitors C3 connected in series are connected to the second input end of the first converter U1;

[0090] N second electrolytic cells R2, wherein the input end or the output end of each second electrolytic cell R2 is provided with a second switch, each second electrolytic cell R2 is respectively connected in parallel with a different third capacitor C3 through the second switch, and each second electrolytic cell R2 is used to electrolyze water to produce hydrogen when powered on;

[0091] Among them, when it is necessary to shut down the second target electrolytic cell, the second switch connected to the second target electrolytic cell is opened; when resuming the operation of the second target electrolytic cell, the second switch connected to the second target electrolytic cell is closed, and the second target electrolytic cell is one of the N second electrolytic cells R2.

[0092] It should be understood that when it is necessary to add electrolytic cells to increase the overall efficiency of the system in producing hydrogen by electrolyzing water, the N second electrolytic cells R2 and N third capacitors C3 that need to be added are directly connected in parallel with the first converter U1, and power is supplied to the N second electrolytic cells R2 through the first converter U1 to realize the addition of electrolytic cells.

[0093] The third capacitor C3 is connected in series to convert the voltage V output by the first converter U1 bus Specifically, the first ends of the N third capacitors C3 connected in series are connected to the second output end of the first converter U1, and the second ends of the N third capacitors C3 connected in series are connected to the second input end of the first converter U1, so that the first converter U1 supplies power to each of the N third capacitors C3, and each third capacitor C3 is connected in parallel to a second electrolytic tank R2, thereby supplying power to each second electrolytic tank R2.

[0094] The second electrolytic cell R2 is used for electrolyzing water to produce hydrogen, wherein the second electrolytic cell R2 is connected in parallel with a first capacitor C1, and the voltage V output by the first converter U1 is converted by the first capacitor C1. bus The divided voltage is used to electrolyze water to produce hydrogen. The positive electrode and the negative electrode of each second electrolytic cell R2 are connected to a pipeline, and the generated hydrogen and oxygen are collected through the pipeline.

[0095] In an embodiment of the present application, the water electrolysis hydrogen production system also includes: N third capacitors C3, the N third capacitors C3 are connected in series, the first ends of the N third capacitors C3 connected in series are connected to the second output end of the first converter U1, and the second ends of the N third capacitors C3 connected in series are connected to the second input end of the first converter U1; N second electrolytic cells R2, the input end or output end of each second electrolytic cell R2 in the N second electrolytic cells R2 is provided with a second switch, each second electrolytic cell R2 is connected in parallel with a different third capacitor C3 through the second switch, and each second electrolytic cell R2 is used to electrolyze water to produce hydrogen when powered on. In this way, when it is necessary to shut down the second target electrolyzer, the second switch connected to the second target electrolyzer is opened; when resuming operation of the second target electrolyzer, the second switch connected to the second target electrolyzer is closed. The second target electrolyzer is one of the N second electrolyzers R2. Since the second electrolyzers R2 are connected in parallel to each other, stopping the operation of the second target electrolyzer will not affect the normal operation of other second electrolyzers R2, thereby improving the efficiency of preparing hydrogen by electrolyzing water.

[0096] In one embodiment, the water electrolysis hydrogen production system further comprises:

[0097] N second voltage equalizing units U4 are connected in series, and each of the second voltage equalizing units U4 is respectively connected in parallel with a different third capacitor C3, the first ends of the N second voltage equalizing units U4 connected in series are connected to the second output end of the first converter U1, the second ends of the N second voltage equalizing units U4 connected in series are connected to the second input end of the first converter U1, and each first voltage equalizing unit U2 is used to adjust the voltage of each third capacitor C3 so that the voltage of each third capacitor C3 is the same.

[0098] It should be understood that during the process of hydrogen production by electrolysis of different second electrolyzers R2, the internal resistance of the electrolyzer changes due to factors such as the electrolyte flow rate and parameter aging of the electrolyzer, resulting in fluctuations in hydrogen production efficiency and a decrease in the efficiency of hydrogen production by electrolysis of the entire system. To avoid this situation, it is necessary to control the operating voltage of each second electrolyzer R2 to be the same, so that each second electrolyzer R2 can produce hydrogen by electrolysis of water according to the set power.

[0099] The second voltage balancing unit U4 is used to adjust the voltage of each first capacitor C1 so that the voltage of each third capacitor C3 is the same, thereby achieving that each first electrolyzer R1 can electrolyze water to produce hydrogen with the same input voltage, thereby avoiding the situation where different first electrolyzers R1 have different power of electrolyzing water to produce hydrogen.

[0100] The second voltage balancing unit U4 may be a resistor, at least two diodes or a voltage stabilizing diode D1.

[0101] In an embodiment of the present application, the water electrolysis hydrogen production system also includes N second voltage equalizing units U4, the N second voltage equalizing units U4 are connected in series, and each second voltage equalizing unit U4 is respectively connected in parallel with a different third capacitor C3, the first end of the N second voltage equalizing units U4 connected in series is connected to the second output end of the first converter U1, and the second end of the N second voltage equalizing units U4 connected in series is connected to the second input end of the first converter U1, and each first voltage equalizing unit U2 is used to adjust the voltage of each third capacitor C3 so that the voltage of each third capacitor C3 is the same, thereby avoiding the problem of fluctuations in hydrogen production efficiency due to changes in the internal resistance of the electrolytic cell, and a decrease in the efficiency of the entire system for hydrogen production by water electrolysis.

[0102] In one embodiment, the water electrolysis hydrogen production system further comprises:

[0103] N third converters U5, wherein a first input end of each third converter U5 of the N third converters U5 is connected to a first end of a third capacitor C3, a first output end of each third converter U5 is connected to a second end of the same third capacitor C3, and each third converter U5 is used to convert an input direct current into a direct current of different magnitudes;

[0104] N fourth capacitors C4, each of the N fourth capacitors C4 is respectively connected in parallel with a different second electrolytic tank R2, a first end of each fourth capacitor C4 is connected to a second input end of a third converter U5, and a first end of each fourth capacitor C4 is connected to a second output end of the same third converter U5.

[0105] The third converter U5 is a direct current / direct current (DC / DC) converter, and the third converter U5 is used to convert the input direct current into direct currents of different magnitudes, and the third converter U5 is used to control the second electrolyzer R2 to electrolyze water to produce hydrogen at different set powers. The fourth capacitor C4 is used to filter the voltage input to the second electrolyzer R2 to stabilize the voltage input to the second electrolyzer R2.

[0106] It should be understood that for different second electrolyzers R2, their working environments are different, and different working powers need to be set for them so that each second electrolyzer R2 can produce hydrogen with a higher efficiency of hydrogen production by electrolysis of water. In the embodiment of the present application, by setting the third converter U5 and the fourth capacitor C4, the second electrolyzer R2 is connected in parallel with the fourth capacitor C4 and the third converter U5, so that the hydrogen production power of the second electrolyzer R2 can be controlled by adjusting the conversion parameters of the third converter U5.

[0107] In the embodiment of the present application, the water electrolysis hydrogen production system also includes: N third converters U5, the first input end of each third converter U5 in the N third converters U5 is connected to the first end of a third capacitor C3, the first output end of each third converter U5 is connected to the second end of the same third capacitor C3, and each third converter U5 is used to convert the input DC current into a DC current of different sizes; N fourth capacitors C4, each fourth capacitor C4 in the N fourth capacitors C4 is respectively connected in parallel with a different second electrolyzer R2, the first end of each fourth capacitor C4 is connected to the second input end of a third converter U5, and the first end of each fourth capacitor C4 is connected to the second output end of the same third converter U5. In this way, by setting the third converter U5 and the fourth capacitor C4, the second electrolyzer R2 is connected in parallel with the fourth capacitor C4 and the third converter U5, so that the hydrogen production power of the second electrolyzer R2 can be controlled by adjusting the conversion parameters of the third converter U5.

[0108] In one embodiment, Fig.10 As shown, the N first electrolytic cells R1 include a working electrolytic cell and a spare electrolytic cell, and / or the N second electrolytic cells R2 include a working electrolytic cell and a spare electrolytic cell.

[0109] It should be understood that since each first electrolyzer R1 works independently and each second electrolyzer R2 works independently, in order to ensure the normal operation of the entire system and the efficiency of hydrogen production by electrolysis of water, a spare electrolyzer can be set up. When a working electrolyzer is abnormal and needs to be shut down for inspection or maintenance, the spare electrolyzer is started to work, thereby achieving that the hydrogen production efficiency of the entire water electrolysis hydrogen production system does not change, thereby improving the stability of the system.

[0110] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0111] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A water electrolysis hydrogen production system, characterized in that: include: a first converter, wherein the first input terminal and the first output terminal of the first converter are used to connect to an AC power source, and the first converter is used to convert an AC current into a DC current; N first capacitors, the N first capacitors are connected in series, a first end of the N first capacitors connected in series is connected to the second output end of the first converter, a second end of the N first capacitors connected in series is connected to the second input end of the first converter, and N is a positive integer greater than or equal to 2; N first electrolytic cells, wherein the input end or the output end of each of the N first electrolytic cells is provided with a first switch, each of the first electrolytic cells is respectively connected in parallel with a different first capacitor through the first switch, and each of the first electrolytic cells is used to electrolyze water to produce hydrogen when powered; Among them, when the first target electrolytic cell needs to be shut down, the first switch connected to the first target electrolytic cell is opened; when the first target electrolytic cell is restored to work, the first switch connected to the first target electrolytic cell is closed, and the first target electrolytic cell is one of the N first electrolytic cells.

2. The water electrolysis hydrogen production system according to claim 1, characterized in that: Also includes: N first voltage equalizing units are connected in series, and each of the first voltage equalizing units is respectively connected in parallel with a different first capacitor, the first ends of the N first voltage equalizing units connected in series are connected to the second output end of the first converter, and the second ends of the N first voltage equalizing units connected in series are connected to the second input end of the first converter, and each first voltage equalizing unit is used to adjust the voltage of each first capacitor so that the voltage of each first capacitor is the same.

3. The water electrolysis hydrogen production system according to claim 2, characterized in that: Also includes: N second converters, wherein a first input end of each second converter of the N second converters is connected to a first end of a first capacitor, a first output end of each second converter is connected to a second end of the same first capacitor, and each second converter is used to convert an input direct current into a direct current of a different magnitude; N second capacitors, each of the N second capacitors is connected in parallel with a different first electrolytic cell, a first end of each second capacitor is connected to a second input end of a second converter, and a first end of each second capacitor is connected to a second output end of the same second converter.

4. The water electrolysis hydrogen production system according to claim 2, characterized in that: Each of the N first voltage balancing units is a resistor, wherein: The input end of the resistor is connected to the input end of the first capacitor, and the input end of the resistor is also connected to the output end of an adjacent resistor or the second output end of the first converter; The output end of the resistor is connected to the output end of the first capacitor, and the output end of the resistor is also connected to the input end of an adjacent resistor or the second input end of the first converter.

5. The water electrolysis hydrogen production system according to claim 2, characterized in that: Each of the N first voltage balancing units is a voltage stabilizing diode, wherein: The input end of the voltage zener diode is connected to the input end of the first capacitor, and the input end of the voltage zener diode is also connected to the output end of an adjacent voltage zener diode or the second output end of the first converter; The output end of the voltage zener diode is connected to the output end of the first capacitor, and the output end of the voltage zener diode is also connected to the input end of an adjacent voltage zener diode or the second input end of the first converter.

6. The water electrolysis hydrogen production system according to claim 2, characterized in that: Each of the N first voltage balancing units is composed of at least two rectifier diodes, which are connected in series. The input end of the series-connected rectifier diodes is connected to the input end of the first capacitor, and the input end of the series-connected rectifier diodes is also connected to the output end of the adjacent series-connected rectifier diodes or the second output end of the first converter; The output end of the series-connected rectifier diodes is connected to the output end of the first capacitor, and the output end of the series-connected rectifier diodes is also connected to the input end of an adjacent series-connected rectifier diode or the second input end of the first converter.

7. The system for producing hydrogen by electrolysis of water according to any one of claims 1 to 6, characterized in that: Also includes: N third capacitors, the N third capacitors are connected in series, a first end of the N third capacitors connected in series is connected to the second output end of the first converter, and a second end of the N third capacitors connected in series is connected to the second input end of the first converter; N second electrolytic cells, wherein the input end or the output end of each of the N second electrolytic cells is provided with a second switch, each of the second electrolytic cells is respectively connected in parallel with a different third capacitor through the second switch, and each of the second electrolytic cells is used to electrolyze water to produce hydrogen when powered; Among them, when the second target electrolytic cell needs to be shut down, the second switch connected to the second target electrolytic cell is opened; when the second target electrolytic cell is restored to work, the second switch connected to the second target electrolytic cell is closed, and the second target electrolytic cell is one of the N second electrolytic cells.

8. The water electrolysis hydrogen production system according to claim 7, characterized in that: Also includes: N second voltage balancing units, the N second voltage balancing units are connected in series, and each of the second voltage balancing units is respectively connected in parallel with a different third capacitor, the first ends of the N second voltage balancing units connected in series are connected to the second output end of the first converter, the second ends of the N second voltage balancing units connected in series are connected to the second input end of the first converter, and each first voltage balancing unit is used to adjust the voltage of each third capacitor so that the voltage of each third capacitor is the same.

9. The water electrolysis hydrogen production system according to claim 7, characterized in that: Also includes: N third converters, wherein a first input terminal of each of the N third converters is connected to a first terminal of a third capacitor, a first output terminal of each of the third converters is connected to a second terminal of the same third capacitor, and each of the third converters is used to convert an input direct current into a direct current of a different magnitude; N fourth capacitors, each of the N fourth capacitors is respectively connected in parallel with a different second electrolytic cell, a first end of each fourth capacitor is connected to a second input end of a third converter, and a first end of each fourth capacitor is connected to a second output end of the same third converter.

10. The water electrolysis hydrogen production system according to claim 7, characterized in that: The N first electrolytic cells include a working electrolytic cell and a spare electrolytic cell, and / or the N second electrolytic cells include a working electrolytic cell and a spare electrolytic cell.

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